I think the basic logic was outlined long ago by one of our mutual heroes, Jane Jacobs. She attempted to understand the city by stepping out her front door, analyzing a stretch of Hudson Street in the Village. Jacobs compared the crowded sidewalk to a spontaneous “ballet,” filled with people from different walks of life. While urban planners had long derided such neighborhoods for their inefficiencies – that’s why Robert Moses, the "master builder" of New York, wanted to build an eight lane elevated highway through Soho and the Village – Jacobs argued that these casual exchanges were essential. She saw the city not as a mass of buildings, but as a vessel of empty spaces, in which people interacted with other people.

These sidewalk conversations came with real benefits. According to Jacobs, the virtue of Hudson Street was that it encouraged the “mingling of diversity,” allowing city dwellers to easily exchange information. The end result was a constant churn of ideas, as strangers learned from each other - “knowledge spillovers.”

What’s interesting is that the sheer disorder of the metropolis maximizes the amount of spillover. As Jacobs once wrote, “By its nature, the metropolis provides what otherwise could be given only by traveling; namely, the strange.” Cities force us to interact with strangers and with the strange. They pry the mind open. And that is why they are the idea that has unleashed so many of our new ideas.

The Talking Heads are one of my favorite bands, and you have a terrific section on the band's brilliant frontman, David Byrne, who says the city is like a giant "sonic blender," with "every street a mix tape." Cities have long been hotbeds of musical and artistic innovation, but do you see any connection between this and their role in stimulating technological innovation and economic progress?

I see it as resulting from the same basic phenomenon, which is that blending of knowledge into new forms. In the book, David (one of my favorite musicians, too) talks about how he'd bicycle around downtown Manhattan, eavesdropping on all the different forms of music playing late at night. There were Latin jazz clubs and Nigerian music halls, punk rock at CBGB and whatever was playing at the Warhol Factory. His genius was to blend all these sounds together.

While it’s tempting to discount these urban interactions – what could possibly emerge from a late night bicycle ride? – they actually come with impressive payoffs. Look, for instance, at a study led by Adam Jaffe, an economist at Brandeis University. He analyzed the paper trail of patent citations, which is the list of previous inventions cited in every patent application. Jaffe found that innovation is largely a local process, so that citations are nearly ten times as likely to come from the same metropolitan area as a control patent. This suggests that inventors are inspired by other inventors in their neighborhood, even when the research involves entirely unrelated subjects.

And this logic doesn’t just apply to patents. David Byrne, after all, wasn’t influenced by the Latin rhythms of some distant musician. Instead, Byrne was seduced by his local dance clubs, blasting those songs he could hear from the sidewalk. It is the sheer density of the city - the proximity of all those overlapping minds - that makes it such an inexhaustible source of creativity.

Silicon Valley has long been seen as the model of high-tech development. One writer called it a "nerdistan" of sprawling highways and office parks, tremendously dependent on the car and lacking the density, walkability, fabric and texture of great urban centers. Why and how exactly does it work?

It's true that Silicon Valley looks like the West Coast antithesis of Jane Jacob's Greenwich Village. And yet, I'd argue that culture of Silicon Valley manages to replicate the essential function of a dense city, which is to foster a diversity of interactions and knowledge spillovers. As Annalee Saxenian points out in her wonderful book, Regional AdvantageSilicon Valley has managed for decades to foster the sort of cross-cutting connections that are essential for innovation. Because the San Jose area has traditionally consisted of small and fledgling startups, these firms have traditionally had to collaborate on projects and share engineers. As a result, it wasn’t uncommon for a scientist at Cisco to be friends with someone at Oracle, or for a co-founder of Intel to offer management advice to a young executive at Apple. These networks often led to high employee turnover, as people jumped from project to project: In the 1980s, for instance, the average tenure at a Silicon Valley company was less than two years.

Jane Jacobs might have frowned upon the sprawl of these California suburbs, but the engineers and scientists have managed to create their own version of Greenwich Village. They don’t bump into each other on the crowded sidewalk or gossip on the stoop of a brownstone. It’s not the ballet of Hudson Street, but it’s still a dance, and it’s the dance that matters.

Recently we've seen evidence of the rise of urban centers like New York, London, even Berlin as high-tech startup centers. Do you see a shift away from the nerdistan model of high-tech and toward a more urban tech?

I just find it slightly ironic that even the researchers inventing all these wonderful tools that allow us to interact remotely, such as email and Skype and Facetime, still organize themselves into local clusters. They know that they need to constantly interact in person, which is why they pay the exorbitant rents of Mountain View or San Francisco or Brooklyn. The city, it turns out, isn't obsolete. Not even close.

Cities, especially big, world-class cities, are notoriously expensive and getting more so. Will this effect their ability to spur creativity?

Absolutely. If I might quote Jacobs one last time: "Old ideas can sometimes use new buildings. New ideas must use old buildings.” She might have been exaggerating a bit, but Jacobs point was that the most innovative people tend to cluster in the cheaper (and older) parts of town. Stewart Brand made a similar point in How Buildings Learn, as he explored the intertwined relationship between so-called Low Road Buildings - think of the Silicon Valley garage or MIT's famed Building 20 - and the birth of many great ideas.

Cheap rents are part of the explanation, but they're not the only thing that matters. These Low-Road spaces also tend to be flexible, allowing creative tinkerers to remake the room in their image.

I think we need to ensure that we don't surrender too much of our cities to the loveliness of upscale boutiques, fancy espresso bars and high-end restaurants. Money in a metropolis typically buys isolation - we get a little peace of mind and our very own parking space - but the creativity of a city depends on our constantly mixing and mingling.

That said, I have no doubt that the best cities will always maintain a few Low Road neighborhoods. The Greenwich Village described by Jacobs ceased to exist decades ago - longshoreman no longer loiter in the bars alongside poets - but New York City has continued to supply its poor creators with a wealth of other spaces. There was Soho and then Soho became a mall. Williamsburg was hip until it was too hip. Nevertheless, there are still so many corners left in Chinatown and Brooklyn and Queens and the Bronx. When people start complaining that all the suffering artists in Staten Island are being evicted by yuppies, I'll start to worry. Until then, I have little doubt that our cities will manage to survive the problem of too many rich people.

About the Author

Richard Florida is Co-founder and Editor at Large of CityLab.com and Senior Editor at The Atlantic. He isdirector of the Martin Prosperity Institute at the University of Toronto and Global Research Professor at NYU.
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